The 300 PCS Foam Board Fasteners Washers by QuZCarious are dome spring washers made of stainless steel. They are designed for the installation of panels and come in a package size of 8.86 x 6.3 x 2.05 inches, weighing 1.05 pounds. The fastener size is M2, with an outside diameter of 1.1 inches. These fasteners are ideal for use in various industrial and commercial applications requiring reliable and durable hardware solutions.